The invention relates to a winch for ropes, particularly for running rigging, such as halyards and sheets on sailing vessels. Such winches normally have a winch drum rotatable in a hauling direction, which is fitted to a base part such as a winch foot or base mounted e.g. on a boat deck. The winch drum is driven by means of a winch gear.
Winches driven by hydraulic or electric motors are already known, e.g. from the brochure HARKEN Yacht Equipment 1995 of HARKEN Piwaukee, Wis., USA, pp 166-183. The motors are flanged to the underside of the winches, which leads to the disadvantage that the motor gear unit must be installed under the deck and the deck area is weakened by a relatively large opening for the passage of the driving shaft flange. Frequently the necessary space is not available at the most favourable point for installing the winch and the motor is a hindrance in the passage to the aft cabins or the interior of the sailing yacht. Even in the case of a costly lining of the motor gear unit the head space is frequently impaired, which constitutes a particular accident risk when at sea. The fitting of such a motor winch to a mast for operating the halyards is scarcely possible.
The object of the invention is to create a very compact motor winch, which largely obviates limitations with respect to the installation locations.
This object is solved by a winch having the features of claim 1.
As a result of the completely integrated fitting of the motor within the winch body, which need not be any larger than a manually operable winch, all restrictions concerning the installation location are obviated. The winch can be located at the point ensuring the least troublesome run of the ropes to be operated by it such as halyards or sheets and where it is least in the way on the deck. It is merely necessary to lay the supply ropes, which can normally take place between the deck structure and a top covering of the cabin. The fitting to the mast is also possible with a conventional winch bracket.
In the case of a construction with an electric motor there is a control unit with a power contactor, which is controlled by means of a weak current control circuit by an operating switch on the deck. The control can also incorporate an excess current fuse protection similar to an automatic cutout, which in addition to the protection function serves to limit a maximum tensile force or pull. Due to the proportionality between the pull and the power consumption even in the case of an accidental excessively long operation, it is possible to prevent overloading of the rope or the sail connected thereto.
When reference is made hereinbefore to ropes, this covers all elongated, flexible pulling or tension elements, which can be placed around a winch drum.
The motor is preferably located in a tubular supporting body and can be installed there with a rotation axis parallel to the winch axis. The tubular supporting body on which the winch drum can be installed by means of needle bearings, constitutes at the same time a both light and stable support structure for the winch drum and leads to a good transfer to the winch foot of the considerable rope forces acting on the winch.
The winch preferably has an additional manual drive, such as in the case of mechanical winches, by means of which it is possible to operate a winch crank insertable in the upper winch head. For this purpose the driving shaft can project eccentrically through the motor area and can also run by the somewhat eccentrically positioned motor.
To enable the motor winch to also haul a rope with the free end in passage operation without mechanical intervention by an operator for tightening the rope, use can be made of a per se known selftailing device, which forms the head of the winch drum and into which the rope is introduced by means of a guide device. Preferably the width of the gripping groove is variable to permit adaptation to different rope diameters, the lower groove boundary possibly being an upper flange of the winch drum and the upper groove boundary is a resiliently axially movable circular disk.
The motor can be a geared motor with an integrated motor gear, e.g. an epicyclic gear, which forms a gear prestage. The motor is preferably a direct current shunt-wound motor, which has a very favourable speed/torque characteristic for the present case, i.e. its torque increases with decreasing speed. Through a high idling speed of approximately 14,000 revolutions per minute, high power can be supplied for a small size. The gear prestage reduces this speed by 3 to 5 times, so that in the following winch gear stages with a lower toothed wheel numbers the sought winch drum idling speed of approximately 80 to 100 revolutions per minute can be achieved. In the case of a winch drum diameter of approximately 100 mm, this leads to a rope hauling speed of between 25 and 30 meters per minute, which is ideal for uses on yachts.
The winch gear and motor gear are preferably non-self-locking spur gears, which have a very high efficiency compared with the conventionally used worm gears. This more particularly applies if in preferred manner the winch gear runs in the oil bath, which can be made permanently maintenance-free by corresponding lubricants. This obviates the need for time-consuming, difficult periodic winch maintenance on board.
The winch gear is preferably located in the foot and contains three gear planes, which in each case form a gear stage. They can be constructed from at least two disk-like, stacked blanks and one of the blanks can be formed by the supporting body for the winch drum. Preferably the transmission direction is from bottom to top, i.e. the motor shaft projects through to the end of the winch base and the individual gear stages are built up above it, so that then the final gear stage reaches and can drive with a transmission toothed wheel the inner edge of the winch drum.
Freewheel locking mechanisms prevent a reversal of the winch drum and at the same time ensure that in the case of motor drive there is no concomitant rotation of the manual drive train, so that an accidentally fitted winch crank cannot give rise to accident risks. Advantageously a freewheel mechanism disconnects the motor in the case of manual operation, so that it does not have to be concomitantly rotated.
The known motor-driven winches are exclusively provided for hauling a rope, i.e. for conveying in one direction. However, there is often a need for veering or easing away a rope, i.e. loosening it somewhat in controlled manner. This is in particular necessary for trimming the sails. According to a preferred embodiment of the invention the winch can be provided with a veering means, which contains an electric control mechanism with which the tensioned rope can be loosened. The electric motor can be used as a controlled brake.
Since as a result of the running back of the winch drum and therefore the drive, the manual drive cannot simply be disconnected by means of a freewheel mechanism, in this case the manual drive is preferably engaged by means of a manually operable clutch.
To be able to perform a reversal of the winch drum counter to the hauling direction, the winch drum freewheel mechanism must be disconnected. This can take place by electrical operation, e.g. by electromagnets or electric servomotors, which disengage the retaining pawls of the freewheel mechanism during the reversing process and maintain same there. As the retaining pawls are normally braced if the winch is under the tension of the rope, said bracing effect can be eliminated in that the motor is firstly moved somewhat in the hauling direction, e.g. by a fraction of the amount corresponding to a locking mechanism division and then the pawls are disengaged. If then the winch drum rotates back under the tension of the rope, the motor also runs backwards. On reaching a preset return speed, which can be monitored by means of a revolution indicator, the control device can connect in a braking resistance means, which limits the reverse speed by the motor now running as a motor brake. Said electric braking resistance means need not be made too large, because the reversing function is normally limited to a limited release.
Said novel veering device, which is also advantageous for other motor winch types, is operated by a switch knob independent of the operating switch for hauling. However, it is also possible to use other control devices, e.g. a joystick. After veering the rope and releasing the operating switch the control device for reengaging the winch drum freewheel mechanism can control the motor briefly in the hauling direction again until the winch drum is almost stationary or runs somewhat in the hauling direction, so as to avoid an excessively hard engagement of the retaining pawls following the release thereof.
If during easing away the rope runs counter to the hauling direction, it could arise that it runs out of the selftailing device. Thus, preferably there is a resilient hold-back lever on the selftailing device and behind which the rope is placed and which is at a considerable circumferential distance from the guide device, i.e. the guide finger, which raises the rope from the winch drum into the selftailing groove. Thus, the rope is guided on both sides of the selftailing groove and acts in both direction. This novel hold-back lever is also advantageous for other winches with a reversing function.
The rope is maintained on the outer surface of the winch drum by friction with self-amplification, i.e. the initial rope tension applied by the selftailing device is amplified by several coils of the rope over the winch drum. Conventional winch drums are roughened or knurled on the outside for increasing the friction factor, but this is not very protective of the rope and damages the surface thereof. It is already known to provide the winch drum with numerous, uniformly circumferentially distributed longitudinal ribs. Within the scope of the invention it has been found that for winches of all types a particularly good ratio between the retaining force and rope protection can be achieved if the longitudinal ribs are provided pairwise with a relatively large, mutual circumferential spacing. There is then an alternation of a few closely juxtaposed ribs with large circumferential spacings, e.g. on the circumference four groups of in each case two closely juxtaposed ribs. As a result the rope is brought into a relatively pronounced polygonal shape, obviously with rounded sides, which ensures a good force transfer in the case of lower rope stressing.
These and further features can be gathered from the claims, description and drawings and the individual features can be implemented singly or in the form of subcombinations in an embodiment of the invention and in other fields and can represent independently protectable constructions for which protection is hereby claimed. The subdivision of the application into individual sections and the subheadings in no way restrict the general validity of the statements made thereunder.